Evenly Distributing Workload and Providing a Predictable Failover Scenario in a Data Replication System

1. A method for distributing load in a data replication system comprising a first storage device and a second storage device, the method comprising: generating an I/O request for processing in one of a first storage resource group and a second storage resource group; directing the I/O request to the first storage device and mirroring a copy of the I/O request to the second storage device in the event the I/O request is to be processed in the first storage resource group; and directing the I/O request to the second storage device and mirroring a copy of the I/O request to the first storage device in the event the I/O request is to be processed in the second storage resource group; in the event the I/O request is to be processed in the first storage resource group but communication with the first storage device fails, redirecting the I/O request to the second storage device; and in the event the I/O request is to be processed in the second storage resource group but communication with the second storage device fails, redirecting the I/O request to the first storage device.

2. The method of claim 1 , wherein the first storage resource group comprises a first logical subsystem (“LSS”) group and the second storage resource group comprises a second logical subsystem (“LSS”) group.

3. The method of claim 1 , wherein the first storage resource group comprises a first group of logical volumes and the second storage resource group comprises a second group of logical volumes.

4. The method of claim 1 , wherein: directing the I/O request to the first storage device and mirroring a copy of the I/O request to the second storage device comprises directing the I/O request to a first server in the first storage device and mirroring a copy of the I/O request to a first server in the second storage device, wherein the first servers are associated with the first storage resource group; and directing the I/O request to the second storage device and mirroring a copy of the I/O request to the first storage device comprises directing the I/O request to a second server in the second storage device and mirroring a copy of the I/O request to a second server in the first storage device, wherein the second servers are associated with the second storage resource group.

5. The method of claim 1 , wherein each of the first storage resource group and the second storage resource group contains an equal number of resources.